TY - CHAP M1 - Book, Section TI - CHORIONIC VILLUS SAMPLING A1 - Wapner, Ronald J. A1 - Toy, Eugene C. A2 - Fleischer, Arthur C. A2 - Toy, Eugene C. A2 - Lee, Wesley A2 - Manning, Frank A. A2 - Romero, Roberto J. PY - 2015 T2 - Sonography in Obstetrics and Gynecology: Principles & Practice, 7e AB - DefinitionsChorionic villus sampling (CVS): an invasive procedure performed for first-trimester prenatal diagnosis. CVS is typically performed between 70 and 91 days after the LMP. In the procedure, tissue is withdrawn from the villi (vascular fingers) of the chorion, a part of the placenta, and examined.Chorion frondosum: the cellular, outermost extraembryonic membrane, composed of trophoblastic cells, and develops villi, and forms the fetal component of the placenta.Fluorescent in situ hybridization (FISH): rapid method of assessing targeted chromosomal abnormalities such as trisomy 21, 18, or 13.First-trimester screening: a method of screening for chromosomal abnormalities in the first trimester using two biochemical tests, PAPP-A and hCG as well as sonographic nuchal translucency measurement. SN - PB - McGraw-Hill Education CY - New York, NY Y2 - 2024/10/03 UR - obgyn.mhmedical.com/content.aspx?aid=1106709080 ER -